charlie@oakhill.UUCP (Charlie Thompson) (11/16/89)
I am looking for software implementations of a Costas Loop. I have the original old paper written by the man himself but I was looking for someone who might have done this in software such as DSP code for one of the DSP's or even C for that matter. Any leads would be appreciated. -Charlie Thompson
esker@abaa.uucp (Lawrence Esker) (11/17/89)
In article <2628@radio.oakhill.UUCP> charlie@oakhill.UUCP (Charlie Thompson) writes: >I am looking for software implementations of a Costas Loop. I >have the original old paper written by the man himself but I >was looking for someone who might have done this in software >such as DSP code for one of the DSP's or even C for that matter. >-Charlie Thompson I've found that the Costas loop is not very good compared to some later developments. It was also impossible to convert to a digital form (as hardware counters, multipliers, etc.) Get the book Phaselock Techniques by Floyd M. Gardner and read chapter 11. It presents several evolved forms, such as the Early-Late gate and the Transition Tracking Loop that are superior in performance than the Costas loop, are hybrid digital/analog designs, and can trace their functional for back to the Costas loop. I've personally designed an all digital version of the Transition Tracking Loop and it was an order of magnetude less complexity than an all digital version of the Costas loop would be. Admittadly, this has nothing to do with DSP or C code, but if an all digital hardware solution is obvious from the theory and simpler to design, I would think a software solution would be obvious and computationally less expensive. -- ---------- Lawrence W. Esker ---------- Modern Amish: Thou shalt not need any computer that is not IBM compatible. UseNet Path: __!mailrus!sharkey!itivax!abaa!esker == esker@abaa.UUCP